Yet another way of testing for equality is to use 'EqualEntries', since this works for Vectors and Matrices but also for other container types such as lists.

M1:=Matrix([[1,0],[0,1]]):
M2:=Matrix([[1,0],[0,1]]):

EqualEntries(M1,M2);

                                 true

Another workaround:

DrawGraph(G, stylesheet = [edgethickness = .1]);

Your tasks are probably too small, so that the overhead of starting a Task will dominate the execution time. Increase the upper limit of the range in the add routine to, e.g., 10,000,000 and then you may find that the parallel execution is faster.

It looks like it is fixed in Maple 14.00 -- an error message is returned.